Resolved issue SANKORE-412

src/gui/UBDocumentNavigator.cpp

@@ -450,6 +450,7 @@ void UBDocumentNavigator::onSelectionChanged()
  */
 void UBDocumentNavigator::onMovedToIndex(int index)
 {
+    if(index < mThumbnails.size()){
         UBSceneThumbnailNavigPixmap* pItem = dynamic_cast<UBSceneThumbnailNavigPixmap*>(mThumbnails.at(index));
         if(NULL != pItem)
         {
@@ -458,3 +459,4 @@ void UBDocumentNavigator::onMovedToIndex(int index)
             centerOn(mCrntItem);
         }
     }
+}